Separating-cylinder for gold-dredgers.



No. 838,579. PATENTED DEC. 18, 1906.

R. H. POSTLETHWAITE.

' SEPARATING CYLINDER FOR GOLD DREDGERS.

' APPLICATION FILED MAY 16. 1905.

THE NGRIJS sarsns ca., WASHINGYON. o. c.

UNITED STATES PATENT OFFICE.

ROBERT H. POSTLETHWVAITE, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TORISDONIRON & LOCOMOTIVE WORKS, OF SAN FRANCISCO, CAIiIFORNIA, ACORPORATION.

SEPARATlNG-CYLINDER FOR GOLD-DREDGERS.

Specification of Letters Patent.

Patented Dec. 18, 1906.

Application filed May 15,1905. Serial No. 260,510.

To aZZ whom it may concern.-

3; Be it known that 1, ROBERT H PosrLn- THWAITE, a subject of the Kingof Great Britain, residing in the city and county of San Francisco,State of California, have invented certain new and useful Improvementsin Separating-Cylinders for Gold-Dredgers; and I hereby declare thefollowing to be a full, clear, and exact description of the same.

The resent invention is designed more particu arly for use in connectionwith that type of gold-dredgers fully set forth and described in LettersPatent of the United States No. 622,532, granted me for an imrovedgold-dredging apparatus on the 1th day of April, 1899, or to that classof dredger used for the recovery of gold wherein the excavated materialis dumped or discharged from the excavating device into the upper end ofa rotary separator or grizzly, the precious metal contained in thematerial discharged therein escaping through the openings orperforations in the wall of the separator or grizzly ontocollecting-tables arranged beneath the same.

The capacity of the machines used for the dredging of gold containingmaterial is mainly controlled by the capacity of the ro tary separatoror grizzly used to treat the material delivered thereto. It is obviousthat if material is fed into the separator in such quantity that thesame cannot be thoroughly worked therein the separator becomes clogged,so to speak, and much of the values of the material will be lost bypassing off with the tailings or worthless portions discharged from thelower open end of the separator or grizzly. The excavating means of thedredger is capable of delivering a greater quantity of material to theseparator or grizzly than can be treated therein as at presentconstructed. This defect it has been sought to remedy by increasing thelength and diameter of the rotary separator or grizzly; but theemployment of such enlarged separators has only partially solved thedifhculty. It is apparent that the diameter and length of the separatorhas confines which it cannot exceed and be operated with any practicalsuccess. For instance, if the diameter be increased beyond a certainsize the interior wall-surface thereof becomes flattened to such anextent that the material to be worked will simply slide over suchsurface, and in due time the perforations will become clogged or filledup. On the other hand, the length of the cylinder-separator cannotexceed approximately twenty feet, else too much power is required topractically work the said separator. Besides, the size of the dredger,with its working mechanism, will not allow for a largercylinder-separator.

The best result is obtained by the use of a cylinder about four feet indiameter with a length of working surface of approximately twenty feet.

The object of the present invention is to substantially double thecapacity of the cylinder-separator, which is accomplished by soconstructing the same as to permit of an initial separation therein toseparate such portion of the material as will not pass through openingsranging in diameter from two and onehalf inches to three inches, thematerial passing through such size openings being treated to a secondworking of the separator, which final working eliminates the preciousmetal from the washed material, the greater portion of base or worthlessmaterial being discharged from the lower open end of thecylinder-separator.

To comprehend the invention, reference should be had to the accompanyingsheet of drawings, wherein Figure 1 is a perspective view of theimproved cylinderseparator. Fig. 2 is a longi tudinal sectional view inelevation taken on the line w 00, Fig. 1, of the drawings; and Fig. 3 isa sectional end view in elevation of the separator.

In the drawings the numeral 1 is used to indicate the inner cylinder ofthe separator, which preferably consists of a series of cylindricalsections 2, united end to end. These sections are preferably composed ofcastvided with a series of circumferentially-disposed perforations oroutlet openings 5, which register with the perforations oroutlet-openings 3 of the inner cylinder 1. These perforations oroutlet-openings of the said lining are slightly less in diameter thanthe outlet 3, the same being about two and one half inches in diameter.The reason for this variance is due to the fact that the openings of thelining gradually enlarge from wear.

The two end sections of the inner cylinder are provided with a circularweb or flange 6, which projects outwardly to a distance of approximately twelve inches. These circular webs or flanges are encircledby a shell or cylinder 7. This outer shell or cylinder, which iscomposed of a series of cylindrical caststeel sections, is formed with aseries of perforations or outlet-openings 8, the size of which openingsor perforations is approximately three-eighths of an inch in diameter orof such diameter as will permit of only fine material escapingtherethrough, said cylinder or shell being held in place andstrengthened by means of a series of spaced longitudinallydisposedT-shaped bars 9 which bars at each end are properly united to thecircular webs or flanges 6 of the inner cylinder, which webs or flanges6 hold the outer cylinder or shell 7 at a given distance away from theinner shell or cylinder 1.

To one of the projecting ends of the inner cylinder or shell 1 issecured an encircling cog-ring 10, which meshes with a drive-cog 1 1.This cog is driven by any suitable mechanism (not shown) for impartingrotation to the rotary separator.

Into the inner cylinder or shell 1 leads a perforated spray-pipe 12, theouter end of which is presumed to connect with a suitable forcepump.(notshown) for delivering water under pressure through the perforatedspraypipe 12 to the interior of the inner cylinder or shell. This pipeis arranged near the upper surface of the said inner cylinder or shell,the size thereof being approximately ten inches in diameter. Saidspraypipe extends substantially the length of the rotary separator, thewater ejected under pressure from its perforations being ejected ontothe material being worked therein.

When situated for work in connection with a dredger, the separator isarranged so as to have a downward inclination.

pipe.

pass through the openings or perforations of the inner cylinder escapetherethrough into the outer shell or cylinder, while the material Suchportions of the material as will foreign substances the material is mucheasier to work and separate. The rotary action of the separator and thewater flowing through the perforations of the inner cylinder or shell issufficient to thoroughly break up and separate such material. The finerportion thereof, together with the gold carried thereby, escape throughthe comparatively small outlet-openings or perforations of the outershell or cylinder and fall onto collectingtables arranged below therotating sepa rator, while the stones and material too coarse to passthrough said openings or perforations gradually Work toward the tail ofthe separator and discharge from the lower open portion 13 of the outershell or cylinder.

By the use of the described separator there is secured approximatelydouble the working surface of an ordinary rotary separator, the initialor primary separation given the material preventing clogging andpermitting a greater quantity of material being treated and handled thanpossible by the use of a single-cylinder separator.

It will be understood that the mentioned size of the perforations forthe inner and outer cylinders or shells may be increased, decreased, orvaried at will, and it will also be understood that the lining describedfor the inner shell or cylinder may be entirely omitted, if so desired.

Having thus described the invention, what is claimed as new, and desiredto be protected. by Letters Patent, is'

1. A rotary grizzly or separator, the same comprising an inner shell orcylinder, a lining therefor, the cylinder and lining having a series ofoutlet-openings in the walls thereof, and an outer shell or cylindersurrounding the inner shell or cylinder, the wall of said outer shell orcylinder being provided with a series of outlet-openings of lessdiameter than those of the inner shell orcylinder.

' 2. A rotary grizzly or separator, the same comprising an inner shellor cylinder, a series of outlet-openings in the Wall thereof, awatersupply pipe extending therein, circular webs connected to the outerface of the inner shell or cylinder, an outer shell or cylinder arrangedintermediate said webs and being slightly less in length than the spacebetween said webs whereby an outlet opening is has formed at one end ofthe cylinder, means for connecting said outer cylinder to the innercylinder, and a series of outlet-openings in the wall of said shell orcylinder, which outlet-openings are of less diameter than those ofthewall of the inner shell or cylinder.

3. A rotary grizzly or separator, the same comprising an inner shell orcylinder, a series of outlet-openings in the wall thereof, awater-supply pipe extending therein, circular webs connected to theouter face of the inner shell or cylinder, an outer shell or cylinderarranged intermediate said webs, and being slightly less in length thanthe space between said webs whereby an outlet-opening is formed at oneend of the cylinder, the inner shell or cylinder extending at one endbeyond the adjacent webs and having connected directly thereto anoperating-gear, the said gear, means for connecting the outer cylinderto the inner cylinder, and a series of outletopenings in the wall ofsaid outer shell or cylinder, which openings are of less diameter thanthose of the wall of the inner shell or cylinder.

" i. A rotary grizzly or separator, the same comprising an inner shellor cylinder, a series of outlet-openings in the wall thereof, awater-supply pipe extending therein, circular webs connected to theouter face of the inner shell or cylinder, an outer shell or cylinderarranged intermediate said webs, the inner shell or cylinder extendingat one end beyond the adjacent webs and having connected di rectlythereto an operating-gear, the said a gear, a series of spacedlongitudinally-disposed bars connecting the outer shell to said webs,and a series of outlet-openings in the wall of-said outer shell orcylinder, which outlet-openings are of less diameter than those of thewall of the inner shell or cylinder.

5. A rotary cylinder or separator comprising a cylinder into which thematerial to be worked is delivered, the same having a series ofoutlet-openings in the wall thereof, and an inner lining for thecylinder, the lining having a series of openings in its wall arranged toregister with the openings in the cylinder and being slightly smallerthan said openings in the cylinder.

6. A rotary separator comprising a cylinder into which the material tobe worked is delivered, the same having a series of outletopenings inthe wall thereof, a water-supply pipe extending into the said cylinderfor delivering the requisite water to the material while being worked,and an inner lining for the cylinder, the lining having a series ofopenings in its wall arranged to register with the openings in thecylinder and being slightly smaller than said openings in the cylinder.

7. A rotary grizzly or separator, the same comprising an inner shell orcylinder into which the material to be worked is delivered, a liningtherefor, a series of outlet-openings in the wall of the lining and inthe wall of the shell or cylinder, a water-supply pipe extending intothe said shell or cylinder for delivering the requisite water to thematerial while being worked, and an outer shell or cylinder securedtoand surrounding the inner shell or cylinder, the wall of said outershell or cylinder being provided with a series of outlet-openings ofless diameter than those of the inner shell or cylinder.

8. A rotary grizzly or separator, the same comprising an imier shell orcylinder, a series of outlet-openings in the wall thereof, awater-supply pipe extending therein, circular webs connected to theouter face of the inner shell or cylinder, an outer shell or cylinderarranged intermediate said webs, and being slightly less in length thanthe space between said webs whereby an outletopening is formed at oneend of the cylinder, a series of spaced longitudinally-disposed barsconnecting the outer shell to the said webs and extending over saidoutlet-opening and a series of outlet-openings in the wall of said shellor cylinder, which outlet-openings are of less diameter than those ofthe wall of the inner shell or cylinder.

9. In a rotary grizzly or separator, a rotary cylinder having a seriesof openings therein, and an inner lining for said screen having a seriesof openings therein of lesser diameter than those of the cylinder andarranged to register therewith at all times, whereby no portion of thewall surrounding said openings is subjected to the direct action of thematerial being operated upon within said cylinder.

In testimony whereof I have hereunto affixed my signature in thepresence of witnesses.

ROBERT H. POSTLETHWAITE.

Witnesses:

N. A. AoKER, D. B. RICHARDS.

